Which is correct

Options

A. An antibody combines with a specific antigen
B. An antibody combines with any antigen
C. All antibodies combine with all type of antigens
D. None of the above

Answer

**Step-by-Step Solution:**

1. **Understanding Antigens and Antibodies:**
- Antigens are foreign substances (like microbes or pathogens) that enter the body and trigger an immune response.
- Antibodies are proteins produced by B cells in response to antigens.

2. **Analyzing the Options:**
- **Option A:** "Antibody combines with the specific antigen."
- **Option B:** "Antibody combines with any antigen."
- **Option C:** "All antibodies combine with all types of antigen."
- **Option D:** "None of the above."

3. **Evaluating Option A:**
- Antibodies are produced specifically for the antigens that the immune system recognizes. This means that each antibody is tailored to bind to a specific antigen.

4. **Evaluating Option B:**
- This option is incorrect because antibodies do not combine with just any antigen; they are specific to certain antigens.

5. **Evaluating Option C:**
- This option is also incorrect as it suggests that all antibodies can bind to all antigens, which is not true. Each antibody has a unique structure that allows it to bind to a specific antigen.

6. **Evaluating Option D:**
- Since Option A is correct, Option D is incorrect.

7. **Conclusion:**
- The correct answer is **Option A:** "Antibody combines with the specific antigen."